CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 55,072	$ 36,151
Accounts receivable (less allowance for losses of $5,102 in 2017 and $3,396 in 2016)	233,831	200,334
Short-term investments	24,709	20,273
Prepaid expenses	23,676	21,039
Income tax receivable	12,206	2,895
Other current assets	2,784	2,268
Total current assets	352,278	282,960
Accounts receivable, long-term	2,333	2,480
Property and equipment, net	147,956	124,268
Other assets:
Goodwill	651,721	650,237
Other intangibles, net	252,874	267,259
Non-current investments and other assets	31,347	30,741
Total assets	1,438,509	1,357,945
Current liabilities:
Accounts payable	9,448	7,295
Accrued liabilities	46,006	55,989
Deferred revenue	304,128	298,217
Total current liabilities	359,582	361,501
Revolving line of credit	0	10,000
Deferred revenue, long-term	1,643	2,140
Deferred income taxes	59,682	68,779
Commitments and contingencies
Shareholders' equity:
Preferred stock, $10.00 par value; 1,000,000 shares authorized; none issued	0	0
Common stock, $0.01 par value; 100,000,000 shares authorized; 48,147,969 shares issued and outstanding as of June 30, 2017 and December 31, 2016	481	481
Additional paid-in capital	586,037	556,663
Accumulated other comprehensive loss, net of tax	(46)	(46)
Retained earnings	499,760	435,876
Treasury stock, at cost; 10,862,030 and 11,381,733 shares in 2017 and 2016, respectively	(68,630)	(77,449)
Total shareholders' equity	1,017,602	915,525
Total liabilities and shareholders' equity	$ 1,438,509	$ 1,357,945

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.